Active brake controls (ABC) have been used to improve vehicle handling under conditions of non-linear wheel operation (i.e., lateral wheel movement relative to a road surface) by applying differential braking forces to left and right wheels of the vehicle with the objective of bringing the vehicle yaw rate and/or slip angle into conformance with desired values provided by a linear reference model. See, for example, the U.S. Pat. No. 5,720,533 to Pastor et al., issued on Feb. 24, 1998, assigned to the assignee of the present invention, and incorporated herein by reference.